hi need help with starting procedure on my bsa round tank the main problem I have is how the oil pump works and what oil to use I have been talk to some people they have told me to use Castrol classic xxl40 sae40 but not sure if that correct also the bike has spark when cable is pulled on the magneto.as you can tell I don't no much about bike this old so any help on this will be good i'm in the uk so if anyone from uk don't mind me call them that will be lot of help to

I personally would never attempt to start a bike in this condition - you don't know what condition the motor is in and you may cause a lot of damage. If you are going to get it restored, it's best in my opinion to overhaul the motor first before trying to get it going.

Arthur is quite right. A bike which has been left for decades in poor conditions will contain unknowns and it is best to find them before risking those near 100 year old parts which will be very difficult to replace. It will be hard enough to source the obvious missing parts. There may even have been an engine problem which caused it to be taken out of use all those years ago.

I suggest you find as much literature as you can concerning your bike and study. There is a lot out there. Knowledge is power.

information was given to me upon purchase was that engine was stripped done and big end was ok piston was good he fit a new chain to gear box apparently bike was try to start but had a weak spark the bike has strong compression and what I can see of spark look ok . so that why I need to find out how the oil pump works and type of oil it takes just see if it will try to fire up

Hand pump if needed feeds from tank direct to crankcase. Suggest you charge the crankcase with some pumps before attempting to start. Might also be useful to put a littleoil in cylinder through plug hole.

Make sure there is feed from tank to mechanical pump and hand pump to engine.

XXL I am sure would be OK unless you are somewhere very cold then it might be best to use XL 30.

To be honest the engine looks the best bit of the bike and obviously has had work done to it. I think encouragement should be given to resurrect another bike that otherwise will probably sit in a corner.